HVAC experts

[Jim Becker]

Do you guys with mini splits just have the one "head" in the room? Or do you run a couple heads to different areas? The ones I'm familiar with can be run both ways, and I assume these don't have ducts. I just wonder how evenly the room is conditioned if you only have one source for cool/warm air.

That would depend upon the physical size of the space and whether or not there are rooms like an office, etc., that are isolated from the main space. My unit has a single inside air handler because it's one big space of only 700 sq ft. But if I had, say...a larger space and/or one with an office, multiple air handlers would be nice to have to distribute the work. The individual air handlers can often be different sizes on a single system, depending on the manufacturer. It's not uncommon for large mini-splits to have as many as four air handlers for residential use and the same design capability can be used for other kinds of spaces. The calculations still need to be done by someone who knows what they are doing to insure that things are sized correctly and the air handlers are placed in the best locations for even performance.

[Tom M King]

I bought a used 6 ton commercial gas pack for my mechanic shop building. The only reason I bought that size was because it was available for $500, six years old, and had never needed work. The building is 24x40, with 12 foot walls, and a weird Gambrel roof framing, with no insulation, and even open eaves. The unit makes it comfortable to work in there when it's really hot, or really cold, but I'm sure it doesn't stay at 72. It would be more than enough if the building was insulated, and closed up, but I don't use it enough to be worth the expense. I think it would make ice in there if it was.

When I had a boat business, I had an oversized gas pack. When doing fiberglass work it was great. I could quickly cool it down to 65 for doing a fiberglass layup, and then turn it back up to normal for letting it kick. A tornado destroyed that building, and I didn't build it back.

[Travis Conner]

He came out and said he has a 3.5 ton in his garage and it doesn't keep up in the summer. That was a 1200 square foot building.

[Travis Conner]

He's going to give me a quote on a 5 ton heat pump system 14 seer.

[Travis Conner]

He's going to give me a quote on a 5 ton heat pump system 14 seer.

He said they do a 7.5 ton unit in and not insulate the building, but then I would need 3 phase. That part didn't make sense to me.

[Travis Conner]

We had a 10 ton unit in our 1 story house and I assure you we never had 3 phase.

[Stan Coryell]

He's going to give me a quote on a 5 ton heat pump system 14 seer.

I would ask him to quote two stage as well. A guess, $400 more. If you can provide the information I asked for, I would be happy to size it. Honestly, I don't know if 5 tons is right or wrong.

[Stan Coryell]

We had a 10 ton unit in our 1 story house and I assure you we never had 3 phase.

Just curious, how come you didn't split it into 2 zones? 24" round is pretty big for a house.

[Travis Conner]

Just curious, how come you didn't split it into 2 zones? 24" round is pretty big for a house.

The house was built with that unit.

[Chris Fairbanks]

Do they have variable speed split units now a days? We have been using them in computer Datacenter’s for a number of years now and it makes life a lot easier since they match their load. Also check out the hvac forum over on garage journal as there is a ton of info there as well. Good luck

[Stan Coryell]

The house was built with that unit.

Recently? I have never seen anything larger than 5 Tons in residential. The static would have to be high or the duct gets too large. You would probably need a 2 HP blower motor.

[Travis Conner]

Maybe my dad didn't know what he was talking about. I just recall him saying 10 tons was as big as they could go without going to a commercial unit. The house was built in 92 or 93

[sean meltvedt]

Travis, my house has a 10 ton in it-it is actually two 5 ton compressors sharing the exchanger. I have a single phase 200amp service.
cheers
Sean

[Bruce Wrenn]

Check with a couple of metal building companies and see who they use for their jobs. These guys will have EXPERIENCE with steel buildings and sizing of units.
It's different from brick and mortar / stick built buildings.

[Mark Bolton]

Where are you coming up with 2.5 tons for 1500 square feet and 12' ceilings? Thats only 30K btu's of cooling? Seems ridiculously low to me for zone 1. I have a simple heating cooling calculator on my phone an punching in zone 1, 1500 sq', 12' ceilings, all else average (window count, insulation, construction, and so on) and it comes up with 52,000 btu's and 48000 suggested for cooling. That puts his number right in the sweet spot (12K btu per ton). What is your reason for always trying to second guess everything? Quincy compressors, sewer lines, power lines, now HVAC guy trying to sham you lol.... Aye carumba.